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| Registros recuperados: 105 | |
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| Pecquerie, Laure; Fablet, Ronan; De Pontual, Helene; Bonhommeau, Sylvain; Alunno-bruscia, Marianne; Petitgas, Pierre; Kooijman, Sebastiaan A. L. M.. |
| Environmental conditions experienced by aquatic organisms are archived in biogenic carbonates such as fish otoliths, bivalve shells and coral skeletons. These calcified structures present an accretionary growth and variations in optical properties - color or opacity - that are used to reconstruct time. Full and reliable exploitation of the information extracted from these structures is, however, often limited as the metabolic processes that control their growth and their optical properties are poorly understood. Here, we propose a new modeling framework that couples both the growth of a biogenic carbonate and its optical properties with the metabolism of the organism. The model relies on well-tested properties of Dynamic Energy Budget (DEB) theory. It is... |
| Tipo: Text |
Palavras-chave: Otolith; Calcification; Metabolism; Bioenergetic model; Food reconstruction; Dynamic Energy Budget theory. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00060/17082/14593.pdf |
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| Colas, Florent; Tardivel, Morgan; Perchoc, Jonathan; Lunven, Michel; Forest, Bertrand; Guyader, Gerard; Danielou, Marie-madeleine; Le Mestre, Sophie; Bourriau, Paul; Antajan, Elvire; Sourisseau, Marc; Huret, Martin; Petitgas, Pierre; Romagnan, Jean-baptiste. |
| In this paper we present the ZooCAM, a system designed to digitize and analyse on board large volume samples of preserved and living metazooplankton (i.e. multicellular zooplankton) and fish eggs > 300 µm ESD. The ZooCAM has been specifically designed to overcome the difficulties to analyse zooplankton and fish eggs in the framework of the PELGAS survey, and provide high frequency data. The ZooCAM fish eggs counts were comparable to those done with a dissecting microscope. The ZooCAM enabled the accurate prediction and fast on board validation of staged anchovy and sardine eggs in almost real time after collection. A comparison with the ZooScan, on a more complex zooplanktonic community, provided encouraging results on the agreement between the 2... |
| Tipo: Text |
Palavras-chave: ZooCAM; In-flow imaging; Fish eggs; Zooplankton; Ecosystemic survey. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00407/51833/52432.pdf |
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| Uriarte, Andres; Ibaibarriaga, Leire; Pawlowski, Lionel; Masse, Jacques; Petitgas, Pierre; Santos, Maria; Skagen, Dankert. |
| La fermeture de la pêche de l’anchois (Engraulis encrasicolus) du Golfe de Gascogne entre 2005 et 2010, en raison de la faible biomasse du stock, a été une opportunité pour estimer la mortalité naturelle à partir de données de campagnes halieutiques issues de l’observation de la présence d’oeufs (DEPM) et de mesures acoustiques, utilisées pour l’évaluation de cette population depuis 1987. En considérant que la mortalité naturelle est constante au cours du temps et que la capturabilité des deux campagnes est identique pour tous les âges, la mortalité naturelle peut être estimée par des modèles log-linéaires appliquées aux séries temporelles de nombres aux âges issues des campagnes, et par des modèles d’évaluations de stock prenant en compte la saison.... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00334/44510/45923.pdf |
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| Petitgas, Pierre. |
| One method to assess fish stocks using a suite of indicators is the traffic light approach. In this approach, the time series of the different indicators are mapped on a common colour scale to highlight alerts that occur when indicators cross reference limit values. Until now, however, the procedure has lacked a statistical framework. Here, we propose the cumulative sum (CUSUM) monitoring scheme as a suitable statistical framework. CUSUM is a statistical process control method that detects deviations from a reference mean, according to defined performance criteria. With the CUSUM monitoring scheme, alarm signals can be triggered when indicators cross defined in-control limits that correspond to defined probabilities of false alarm and non-alarm (i.e.,... |
| Tipo: Text |
Palavras-chave: Integrated assessment; Traffic light approach; Monitoring; CUSUM; Indicators. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6690.pdf |
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| Huret, Martin; Vandromme, Pieter; Petitgas, Pierre; Pecquerie, Laure. |
| Connectivity during early life stages of pelagic fish, defined here by survival probability between spawning and early juvenile habitats, depends on a combination of sufficient food availability and low predator encounter along drift trajectories. For anchovy in the Bay of Biscay, larval transport experiments throughout the spawning season suggest accumulation of early juveniles in the offshore area of the southern Bay, as well as retention over the mid-shelf at mid-latitude. However, late summer-early autumn surveys suggest presence of juveniles only in the former region. From this observation, we set up a bioenergetic individual based model to test for the effect of food availability on survival patterns. The model couples a Lagrangian transport module... |
| Tipo: Text |
Palavras-chave: Connectivity; Larval IBM; Bioenergetics; Zooplankton; Bay of Biscay; European anchovy. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00105/21655/19237.pdf |
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| Hufnagl, Marc; Payne, Mark; Lacroix, Genevieve; Bolle, Loes J.; Daewele, Ute; Dickey-collas, Mark; Gerkema, Theo; Huret, Martin; Janssen, Frank; Kreus, Markus; Paetsch, Johannes; Pohlmann, Thomas; Ruardij, Piet; Schrum, Corinna; Skogen, Morten D.; Tiessen, Meinard C. H.; Petitgas, Pierre; Van Beek, Jan K. L.; Van Der Veer, Henk W.; Callies, Ulrich. |
| Hydrodynamic Ocean Circulation Models and Lagrangian particle tracking models are valuable tools e.g. in coastal ecology to identify the connectivity between offshore spawning and coastal nursery areas of commercially important fish, for risk assessment and more for defining or evaluating marine protected areas. Most studies are based on only one model and do not provide levels of uncertainty. Here this uncertainty was addressed by applying a suite of 11 North Sea models to test what variability can be expected concerning connectivity. Different notional test cases were calculated related to three important and well-studied North Sea fish species: herring (Clupea harengus), and the flatfishes sole (Solea solea) and plaice (Pleuronectes platessa). For sole... |
| Tipo: Text |
Palavras-chave: Ocean circulation; Lagrangian approach; Variability; Marine protected areas; Renewable energy; Wind park; Model intercomparison; Ensemble. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00385/49660/50198.pdf |
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| Certain, G.; Masse, Jacques; Van Canneyt, O.; Petitgas, Pierre; Doremus, G.; Santos, M. B.; Ridoux, Vincent. |
| The present study is a general multivariate analysis of the spatial association between small pelagic fishes and their predators (seabirds, marine mammals and fisheries), using 6 yr (18000 km) of transects surveyed in spring in the Bay of Biscay, France. We describe 4 groups of prey-predator association, with explicit distinction of prey size: (1) terns and anchovies (10 to 15 cm), (2) common dolphins, common murres, sprat and sardine (<20 cm), (3) gannets, horse mackerel and mackerel (15 to 25 cm) and (4) bottlenose dolphin, horse mackerel and mackerel (25 to 40 cm). Our analysis also illustrates the great variability in these associations, with years of strong prey-predator associations followed by years of weak relationships. The analysis allows us... |
| Tipo: Text |
Palavras-chave: Marine top predators; Small pelagic fishes; Spatial associations; Temporal variability; Pelagic ecosystem; Bay of Biscay. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14257/11540.pdf |
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| Huret, Martin; Bourriau, Paul; Doray, Mathieu; Gohin, Francis; Petitgas, Pierre. |
| Fishery annual surveys are shifting towards integrated ecosystem surveys. However, monitoring the whole ecosystem once a year entails special attention to the interpretation of observations, because they only represent a snapshot in the seasonal dynamics of the environment, of a species, or any dynamic process of interest. The dependency of this snapshot to the timing, but also to the duration, of the survey with respect to this seasonal dynamics needs to be considered. Fish stock assessment is only little impacted by the observed timing within a given season, whereas warming, stratification, plankton bloom occurrence, or fish fecundity, are processes rapidly changing especially in spring. Firstly, from independent satellite data, we described the seasonal... |
| Tipo: Text |
Palavras-chave: Ecosystem survey; Anchovy; Sardine; Spawning; Sea surface temperature; Degree day; Bay of Biscay. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00394/50584/51483.pdf |
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| Petitgas, Pierre. |
| The management of marine fish stocks has stayed non-spatial, considering spatial distributions and their consequences on demography as implicit. But the impacts of climate change and the anthropisation of habitats now require to consider spatial procedures explicitly. The work presented here starts with the question of evaluating population abundance, which requires the modelling of spatial distributions (section 1). Then an ecological understanding of the multi-scale nature of distributions is investigated (section 2). Last, we study how demographic population dynamics depends on the spatial organisation of life cycles (section 3). In this work, the approach has been to combine data acquisition at sea with statistical characterisation and modelling. The... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12410/9197.pdf |
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| Petitgas, Pierre; Renard, Didier; Desassis, Nicolas; Huret, Martin; Romagnan, Jean-baptiste; Doray, Mathieu; Woillez, Mathieu; Rivoirard, Jacques. |
| This paper presents a novel application of the geostatistical multivariate method known as min–max autocorrelation factors (MAFs) for analysing fisheries survey data in a space–time context. The method was used to map essential fish habitats and evaluate the variability in time of their occupancy. Research surveys at sea on marine fish stocks have been undertaken for several decades now. The data are time series of yearly maps of fish density, making it possible to analyse the space–time variability in fish spatial distributions. Space–time models are key to addressing conservation issues requiring the characterization of variability in habitat maps over time. Here, the variability in fisheries survey data series is decomposed in space and time to address... |
| Tipo: Text |
Palavras-chave: MAF; Space-time; Habitat; Mapping; Sardine; Bay of Biscay. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00599/71157/69915.pdf |
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| Woillez, M; Poulard, Jean-charles; Rivoirard, Jacques; Petitgas, Pierre; Bez, Nicolas. |
| A series of candidate statistical indices is used in an attempt to capture spatial patterns of fish populations from research survey data. To handle diffuse population limits, indices are designed not to depend on arbitrary delineation of the domain. They characterize the location (centre of gravity and spatial patches), the occupation of space (inertia, isotropy, positive area, spreading area, and equivalent area), statistical dispersion (Gini index and coefficient of variation of strictly positive densities), and microstructure. Collocation between different ages and years is summarized by a global index of collocation. Indices are estimated for hake from a bottom-trawl data series in the Bay of Biscay in autumn of 1987-2004. The study provides a... |
| Tipo: Text |
Palavras-chave: Spatial indices; European hake; Bay of Biscay. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2671.pdf |
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| Petitgas, Pierre; Goarant, Anne; Masse, Jacques; Bourriau, Paul. |
| Petitgas, P., Goarant, A., Masse, J., and Bourriau, P. 2009. Combining acoustic and CUFES data for the quality control of fish-stock survey estimates. - ICES Journal of Marine Science, 66: 1384-1390. |
| Tipo: Text |
Palavras-chave: CUFES; Biscay; Bias; Anchovy; Acoustics; Abundance. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6566.pdf |
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| Doray, Mathieu; Berger, Laurent; Coail, Jean-yves; Vacherot, Jean-philippe; Bavouzet, Gerard; Petitgas, Pierre. |
| The lack of specific Target Strength (TS) values for European anchovy (Engraulis encrasicolus) and sardine (Sardina Pilchardus) in the literature has been pointed out by the Working Group on Acoustic and Egg Surveys for Sardine and Anchovy in ICES Areas VIII and IX. The need for specific small pelagics TS measurements conducted in controlled environments was recognized by the group, to further investigate the adequacy of TS length equation used to derive fish stock estimates for clupeids in European waters. TS is a stochastic variable which largely varies in the wild, in response to changes in physical (tilt angle, depth) or biological (physiology) single fish attributes. The first requirement to make sound TS measurement is to accurately identify of the... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00055/16637/14133.pdf |
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| Petitgas, Pierre; Secor, Dave H.; Mcquinn, Ian; Huse, Geir; Lo, Nancy. |
| Experience has established that the recovery of many collapsed stocks takes much longer than predicted by traditional fishery population models. We put forward the hypothesis that stock collapse is associated with disruption of the biological mechanisms that sustain life-cycle closure of intrapopulation contingents. Based on a review of case studies of nine marine fish stocks, we argue that stock collapses not only involve biomass loss, but also the loss of structural elements related to life-cycle diversity (contingents), as well as the breakdown of socially transmitted traditions (through a curtailed age range). Behavioural mechanisms associated with these structural elements could facilitate recovery of depleted populations. Migratory behaviour is... |
| Tipo: Text |
Palavras-chave: Behaviour; Collapse; Life-cycle diversity; Recovery. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00021/13186/10262.pdf |
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| Huret, Martin; Bourriau, Paul; Gatti, Paul; Dumas, Franck; Petitgas, Pierre. |
| The size and specific gravity of eggs of marine pelagic fish partly determine their dispersal and survival. Using an original dataset of anchovy and sardine eggs, sampled in spring over the last decade in the Bay of Biscay, we provide a parameterization of these properties on ambient water temperature and salinity. We used the density gradient column for measurement of egg specific gravity. The column was also filled with homogeneous water for sinking velocity experiments. For anchovy, these experiments confirm that the effect of egg permeability through the chorion could be neglected when modelling sinking, while it has to be considered for sardine, its perivitelline space representing 78.6% (±6.2%) of the total egg volume, as opposed to 5–10% for most... |
| Tipo: Text |
Palavras-chave: Anchovy; Bay of Biscay; Density gradient column; Egg buoyancy; Egg permeability; Egg size; Sardine. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00346/45676/45326.pdf |
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| Petitgas, Pierre; Doray, Mathieu; Huret, Martin; Masse, Jacques; Woillez, Mathieu. |
| Characterizing the space–time variability in spatial distributions as well as understanding its drivers is basic to designing robust spatial management plans. As a prerequisite, we analyse here how this variability relates to population dynamics in conjunction with environmental conditions. For that, spatio-temporal statistical approaches are needed but seldom used in fisheries science. To fill this gap, we showcase the usefulness of the method of empirical orthogonal functions (EOFs). Guidelines are given to apply the method on a series of gridded maps as derived from fisheries survey dataseries that now span over decades. The method is applied to the series, 2000–2012, of the spatial distributions of European anchovy in the Bay of Biscay at spawning... |
| Tipo: Text |
Palavras-chave: Anchovy; Bay of Biscay; Density-dependence; EOF; Habitat; Spatial distribution. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00222/33365/31907.pdf |
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| Registros recuperados: 105 | |
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